407 research outputs found

    MEDIN Feasibility Study : archiving oil and gas industry site survey data

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    This report was commissioned by the Marine Environmental and Information Network (MEDIN) to investigate the feasibility of collecting oil and gas industry site surveys conducted on the UKCS (UK Continental Shelf) for archive in the MEDIN DAC (Data Archive Centre) network. The archive of three principle data types is explored; information about legacy site surveys, catalogues of information about data products associated with site surveys and actual site survey data, which may include a survey report and enclosures and/or a selection of data e.g. side-scan or multibeam, sample descriptions and seismic profiles. The merits of the collection of these data types are explored alongside the cost implications, from both an oil and gas industry contractor’s and a marine geoscientist’s perspective, thereby enabling MEDIN to better understand and make decisions as to which data to concentrate on. The principles and proposed procedures for carrying out the collection of these data types are outlined however the practical details of these will require agreement should any decision be made to proceed. At this stage a further thorough detailed scope will be required in order to formulate procedures, qualify numbers, define activities, identify resources and plan timescales. The time period for the collection of legacy site surveys will require consideration i.e. how far back it is feasible to collect this information, and whether requests should be phased to include surveys acquired within predetermined time intervals. The size of the actual site survey data holdings, the storage capacity required to archive these and the amount of work involved in processing this data into useable and useful formats will require review. Some of these issues may need to be considered on a case-by-case basis. The procedures themselves will require regular review dependent on the response i.e. the volume, types and condition of data received

    The geochemistry of sea-bed sediments of the United Kingdom Continental Shelf : the North Sea, Hebrides and West Shetland shelves, and the Malin-Hebrides sea area

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    The sea area around the United Kingdom is used for a wide range of human activities all of which have a significant impact on the marine environment. The naturally-occurring concentrations of chemical elements in sea-bed sediments may be enhanced by contaminants introduced by input from rivers and the atmosphere and by more localised sources arising from shipping operations, exploitation of oil and gas, and by direct discharges from drainage systems, sewage outfalls, effluents from industry and waste' disposal at sea. It is therefore important to identify components of sea-floor sediments which are due to the rocks or older sediments from which they are derived, and those which are introduced into the environment. This report presents regional geochemical data for a variety of sediment types occurring in a wide range of environments. Samples have been collected offshore of the eastern coast of the UK where major river systems which drain heavily populated and industrialised catchment areas, such as the Thames, Humber and Tyne, flow into the North Sea, and on the shelf west of Scotland where man's activities have had much less impact. The data presented here provide a baseline for chemical element concentrations in sea-bed sediments against which future work may be assessed. It should therefore be of significance to a diverse range of interests including pollution control, fishing, natural resources, nature conservation, shipping, tourism, recreation, and waste disposal management. In addition the information will be of use to geologists in identifying the source of sea-bed sediments and the underlying glacial deposits

    Vale of York 3-D borehole interpretation and cross-sections study

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    The Vale of York between Doncaster and Scunthorpe in the south and York and Bugthorpe in the north is largely underlain by bedrock of the Sherwood Sandstone Group – one of the regions principal aquifers. Significant superficial deposits of Quaternary age overlie the Sherwood Sandstone. This study aims to investigate the nature of these superficial deposits with respect to their relationship with the underlying aquifer. The Vale of York project area represents a varied glaciated terrain, consisting of pro-glacial finegrained sediments, coarser glaciofluvilal sediments and extensive glacial tills. These diverse superficial units vary in thickness throughout the project area. The hydrogeological nature of the natural superficial sequence is consequently highly variable. Units may be considered as aquitards, while others may act as aquifers, providing a potential pathway to the underlying sandstone. The classification of lithologies as aquifer or aquitard is described in detail in this report. To investigate the hydrogeological nature of the superficial sequence, six east-west and three north-south lithostratigraphical cross-sections were constructed. A range of geoscientific information was considered, including existing geological mapping and over 3000 fully attributed and coded boreholes. The cross-sections show a subdivision of the superficial sequence into lithostratigraphical units. Each unit is described in detail in this report. In addition, a series of thematic maps were generated from the lithological component of the digital borehole data. Total superficial aquifer and superficial aquitard maps show how the lithological nature of the superficial sequence varies across the area. Rockhead elevation and superficial thickness maps indicate where the sandstone aquifer outcrops at the ground surface. In summary, four main lithostratigraphical units overlie the Sherwood Sandstone Group aquifer in the project area: a basal sequence of glaciofluvial sand and gravel (interpreted as a superficial aquifer), glaciolacustrine laminated silt & clay (aquitard), glacial till comprising sandy gravelly clay (aquitard), and a cover sequence of fluvial and aeolian sand, clay and peat (aquifer / aquitard). The correlations illustrate that in certain areas, superficial deposits are thin or absent and that in these areas the Sherwood Sandstone aquifer comes directly to ground surface

    Potential Predictors of Injury Among Pre-Professional Ballet and Contemporary Dancers

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    Injuries occur frequently among ballet and contemporary dancers. However, limited literature exists on injuries to pre-professional dancers in the USA. The goals of this study were to 1. provide a descriptive epidemiology of the incidence of musculoskeletal injuries in an adolescent and young adult dance population and 2. identify parsimonious regression models that could be potentially used to predict injury incidence. The study was based at the University of North Carolina School of the Arts (UNCSA) from Fall 2009 to Spring 2015. An injury was defined as any event that caused a dancer to be seen at the UNCSA Student Health Services and caused the dancer to modify or curtail dance activity for at least 1 day. Injury rate ratios (IRRs) were calculated using negative binomial generalized estimating equations. Models predicting injury rates were built using forward selection, stratified by sex. Among 480 dancers, 1,014 injuries were sustained. Most injuries were to the lower extremity and the result of overuse. There were differences in upper extremity, lower extremity, and traumatic injury rates by demographic subgroups. Among females, the most parsimonious predictive model for injury rates included a self-reported history of depression, age at time of injury, and number of injuries sustained at UNCSA prior to the semester of current injury. Among males, the most parsimonious model was a univariate model with family history of alcohol or drug problems. Strategies for traumatic injury prevention among dancers should be both sex- and style-specific. No differences were observed in overuse injury rates by sex or style, suggesting that generic overuse prevention strategies may not need to be guided by these factors. It is concluded that strategies can be implemented to reduce and mitigate the consequences of injuries if not the injuries themselves

    Surface Roughness and Effective Stick-Slip Motion

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    The effect of random surface roughness on hydrodynamics of viscous incompressible liquid is discussed. Roughness-driven contributions to hydrodynamic flows, energy dissipation, and friction force are calculated in a wide range of parameters. When the hydrodynamic decay length (the viscous wave penetration depth) is larger than the size of random surface inhomogeneities, it is possible to replace a random rough surface by effective stick-slip boundary conditions on a flat surface with two constants: the stick-slip length and the renormalization of viscosity near the boundary. The stick-slip length and the renormalization coefficient are expressed explicitly via the correlation function of random surface inhomogeneities. The effective stick-slip length is always negative signifying the effective slow-down of the hydrodynamic flows by the rough surface (stick rather than slip motion). A simple hydrodynamic model is presented as an illustration of these general hydrodynamic results. The effective boundary parameters are analyzed numerically for Gaussian, power-law and exponentially decaying correlators with various indices. The maximum on the frequency dependence of the dissipation allows one to extract the correlation radius (characteristic size) of the surface inhomogeneities directly from, for example, experiments with torsional quartz oscillators.Comment: RevTeX4, 14 pages, 3 figure

    Generalized harmonic formulation in spherical symmetry

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    In this pedagogically structured article, we describe a generalized harmonic formulation of the Einstein equations in spherical symmetry which is regular at the origin. The generalized harmonic approach has attracted significant attention in numerical relativity over the past few years, especially as applied to the problem of binary inspiral and merger. A key issue when using the technique is the choice of the gauge source functions, and recent work has provided several prescriptions for gauge drivers designed to evolve these functions in a controlled way. We numerically investigate the parameter spaces of some of these drivers in the context of fully non-linear collapse of a real, massless scalar field, and determine nearly optimal parameter settings for specific situations. Surprisingly, we find that many of the drivers that perform well in 3+1 calculations that use Cartesian coordinates, are considerably less effective in spherical symmetry, where some of them are, in fact, unstable.Comment: 47 pages, 15 figures. v2: Minor corrections, including 2 added references; journal version

    Metal Surface Energy: Persistent Cancellation of Short-Range Correlation Effects beyond the Random-Phase Approximation

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    The role that non-local short-range correlation plays at metal surfaces is investigated by analyzing the correlation surface energy into contributions from dynamical density fluctuations of various two-dimensional wave vectors. Although short-range correlation is known to yield considerable correction to the ground-state energy of both uniform and non-uniform systems, short-range correlation effects on intermediate and short-wavelength contributions to the surface formation energy are found to compensate one another. As a result, our calculated surface energies, which are based on a non-local exchange-correlation kernel that provides accurate total energies of a uniform electron gas, are found to be very close to those obtained in the random-phase approximation and support the conclusion that the error introduced by the local-density approximation is small.Comment: 5 pages, 1 figure, to appear in Phys. Rev.

    Using social network sites in Higher Education: An experience in business studies

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    In the past 5 years the impact of Web 2.0 in new generations has been remarkably significant (Pew Research Center, 2010). This paper reports on an experience in the use of Social Network Sites (SNS) to support student involvement with the subject and to develop basic skills. According to students’ opinion, the experience was deemed as positive. They considered that the experience contributed to a higher engagement with the subject and a deeper collaboration with other students and teaching staff. As a result, the majority of students would prefer the use of SNS as a first option if they had to enrol again in the subject. Regarding the relationships between academic performance and use of the SNS, two different student profiles were identified based on usage patterns of the platform. Students with a more intensive use of the site showed a significantly better performance than students with a low usage profile.This work was partially supported by the Junta de Andalucía – FEDER (Proyectos de Excelencia: SEJ-02670

    The type 2 cannabinoid receptor regulates susceptibility to osteoarthritis in mice

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    SummaryObjectiveCannabinoid receptors and their ligands have been implicated in the regulation of various physiological processes but their role in osteoarthritis has not been investigated. The aim of this study was to evaluate the role of the type 2 cannabinoid receptor (Cnr2) in regulating susceptibility to osteoarthritis in mice.MethodsWe analysed the severity of knee osteoarthritis as assessed by the Osteoarthritis Research Society International (OARSI) scoring system in mice with targeted deletion of Cnr2 (Cnr2−/−) and wild type (WT) littermates. Studies were conducted in mice subjected to surgical destabilisation of the medial meniscus (DMM) and in those with spontaneous age-related osteoarthritis (OA).ResultsOsteoarthritis was more severe following DMM in the medial compartment of the knee in Cnr2−/− compared with WT mice (mean ± sem score = 4.9 ± 0.5 vs 3.6 ± 0.3; P = 0.017). Treatment of WT mice with the CB2-selective agonist HU308 following DMM reduced the severity of OA in the whole joint (HU308 = 8.4 ± 0.2 vs vehicle = 10.4 ± 0.6; P = 0.007). Spontaneous age related osteoarthritis was also more severe in the medial compartment of the knee in 12-month old Cnr2−/− mice compared with WT (5.6 ± 0.5 vs 3.5 ± 0.3, P = 0.008). Cultured articular chondrocytes from Cnr2−/− mice produced less proteoglycans in vitro than wild type chondrocytes.ConclusionThese studies demonstrate that the Cnr2 pathway plays a role in the pathophysiology of osteoarthritis in mice and shows that pharmacological activation of CB2 has a protective effect. Further studies of the role of cannabinoid receptors in the pathogenesis of osteoarthritis in man are warranted
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